tmunit.cpp

/* ******************************************************************************* * Copyright (C) 2008-2010, Google, International Business Machines Corporation and * others. All Rights Reserved. ******************************************************************************* */#include <typeinfo>// for 'typeid' to work#include "unicode/tmunit.h"#if !UCONFIG_NO_FORMATTINGU_NAMESPACE_BEGINUOBJECT_DEFINE_RTTI_IMPLEMENTATION(TimeUnit)
/* * There are only 7 time units. * So, TimeUnit could be made as singleton * (similar to uniset_props.cpp, or unorm.cpp, * in which a static TimeUnit* array is created, and * the creatInstance() returns a const TimeUnit*). * But the constraint is TimeUnit is a data member of Measure. * But Measure (which is an existing API) does not expect it's "unit" member * as singleton. Meaure takes ownership of the "unit" member. * In its constructor, it does not take a const "unit" pointer. * Also, Measure can clone and destruct the "unit" pointer. * In order to preserve the old behavior and let Measure handle singleton "unit", * 1. a flag need to be added in Measure; * 2. a new constructor which takes const "unit" as parameter need to be added, * and this new constructor will set the flag on. * 3. clone and destructor need to check upon this flag to distinguish on how * to handle the "unit". * * Since TimeUnit is such a light weight object, comparing with the heavy weight * format operation, we decided to avoid the above complication. * * So, both TimeUnit and CurrencyUnit (the 2 subclasses of MeasureUnit) are * immutable and non-singleton. * * Currently, TimeUnitAmount and CurrencyAmount are immutable. * If an application needs to create a long list of TimeUnitAmount on the same * time unit but different number, for example, * 1 hour, 2 hour, 3 hour, ................. 10,000 hour, * there might be performance hit because 10,000 TimeUnit object, * although all are the same time unit, will be created in heap and deleted. * * To address this performance issue, if there is any in the future, * we should and need to change TimeUnitAmount and CurrencyAmount to be * immutable by allowing a setter on the number. * Or we need to add 2 parallel mutable classes in order to * preserve the existing API. * Or we can use freezable. */TimeUnit* U_EXPORT2
00058TimeUnit::createInstance(TimeUnit::UTimeUnitFields timeUnitField,
UErrorCode& status) {
if (U_FAILURE(status)) {
returnNULL;
}
if (timeUnitField < 0 || timeUnitField >= UTIMEUNIT_FIELD_COUNT) {
status = U_ILLEGAL_ARGUMENT_ERROR;
returnNULL;
}
returnnewTimeUnit(timeUnitField);
}
00071TimeUnit::TimeUnit(TimeUnit::UTimeUnitFields timeUnitField) {
fTimeUnitField = timeUnitField;
}
00076TimeUnit::TimeUnit(constTimeUnit& other)
: MeasureUnit(other) {
*this = other;
}
UObject*
00083TimeUnit::clone() const {
returnnewTimeUnit(*this);
}
TimeUnit&
00089TimeUnit::operator=(constTimeUnit& other) {
if (this == &other) {
return *this;
}
fTimeUnitField = other.fTimeUnitField;
return *this;
}
UBool00099TimeUnit::operator==(constUObject& other) const {
return (typeid(*this) == typeid(other)
&& fTimeUnitField == ((TimeUnit*)&other)->fTimeUnitField);
}
TimeUnit::UTimeUnitFields00106TimeUnit::getTimeUnitField() const {
return fTimeUnitField;
}
00111TimeUnit::~TimeUnit() {
}
U_NAMESPACE_END#endif